Retrofitting Old Preamp with Motorized Volume Control

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.

Jmo

Member
2015-12-14 2:06 pm
Hello, first post here. I can't seem to find on a thread on my exact topic, which seems fairly straightforward. As the title says, I want to update my old NAD 1020 with a motorized volume/remote. Installing the volume control itself seems straightforward but I'm stumped about how to get power to it. I want to tap into the preamp power supply and connect an LM317 for the 5 volts needed but am not sure what the best way to do this is (or even if this is the best option). I can post a schematic if that will help answer the question.

Thanks--John
 
Service manual with Schematic for your pre-amp is available for free here; NAD 1020B Manual - Stereo Pre Amplifier - HiFi Engine

There isn't any 5v power in there right now, only +23.3v and -20.2v. I'd suggest if there is room in the amp housing to solder in and piggy back on the 120VAC switched output a small USB type power supply for your required 5v.

Others may have a better suggestion, but this is where I would start.

Post pictures as I'm interested in this project as well.

Vin
 

Jmo

Member
2015-12-14 2:06 pm

Attachments

  • NAD PS.jpg
    NAD PS.jpg
    109 KB · Views: 372
  • NAD full schematic.jpg
    NAD full schematic.jpg
    257.7 KB · Views: 383
Cheapest solution is to pick off the AC output of the transformer secondary, after the fuses. Add a power resistor in series to drop the supply down to the required input range.
The MV02 requires Power supply : AC9-12V, 3Amp
What documentation came with MV02? post it.
You will lose loundness compensation since the Alps 27K pot does not have a loundness tap!
 
Sorry I missed your reply. I agree with rsavas. if you need 12v then either a power resistor or a voltage divider circuit from the main fused power to get to 12v.

I can't find a schematic for that volume controller. says it comes with a drawing, but I'd want to see it to make sure you can make that kit work if I were you. Maybe contact the seller to get a copy.

The other is, will that large board fit where the original volume control is? that's a big board.

Vin
 
Dunno I had a remote/motorised volume selector on a previous amp.
I realised soon enough that; because I could diddle with it from my chair .. I did.
Much like the TV remote it just encouraged constant/obsessive fiddling.
I eventually 'lost' that amp and it's remote... Happily
Take care in what You wish for
 
I used the MV02

It works well.
Couple of quirky bits that I recall.
When adjusting the volume, i.e. when the motor is turning, there is some quiet digital clicking coming through the audio channels.
When changing channels the software turns the volume all the way down to zero, every time.
You can interupt this by pressing a button (can't remember which one, since I gave this amplifier away as a Birthday present).
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.